/**
 * 
 */
package com.ydy.utils;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.LinkedList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author xuzhaojie
 *
 *         2019年6月5日 下午3:09:23
 */
public class ZipUtil {
	private final static Logger log = LoggerFactory.getLogger(ZipUtil.class);
	private static final int BUFFER_SIZE = 2 * 1024;
	private static final int BUFFER = 512;

	/**
	 * 压缩方法 （可以压缩空的子目录）
	 * 
	 * @param srcPath
	 *            压缩源路径
	 * @param zipFileName
	 *            目标压缩文件
	 *
	 * @return
	 */
	public static boolean zip(String srcPath, String zipFileName) {
		log.info("zip compressing...");
		File srcFile = new File(srcPath);
		List<File> fileList = getAllFiles(srcFile);// 所有要压缩的文件
		byte[] buffer = new byte[BUFFER];// 缓冲器
		ZipEntry zipEntry = null;
		int readLength = 0;// 每次读出来的长度
		try {
			ZipOutputStream zipOutputStream = new ZipOutputStream(new FileOutputStream(zipFileName));

			for (File file : fileList) {
				if (file.isFile()) {// 若是文件，则压缩这个文件
					zipEntry = new ZipEntry(getRelativePath(srcPath, file));
					zipEntry.setSize(file.length());
					zipEntry.setTime(file.lastModified());
					zipOutputStream.putNextEntry(zipEntry);

					InputStream inputStream = new BufferedInputStream(new FileInputStream(file));

					while ((readLength = inputStream.read(buffer, 0, BUFFER)) != -1) {
						zipOutputStream.write(buffer, 0, readLength);
					}
					inputStream.close();
					log.info("file compressed: " + file.getCanonicalPath());
				} else {// 若是目录（即空目录）则将这个目录写入zip条目
					zipEntry = new ZipEntry(getRelativePath(srcPath, file) + "/");
					zipOutputStream.putNextEntry(zipEntry);
					log.info("dir compressed: " + file.getCanonicalPath() + "/");
				}
			} // end for
			zipOutputStream.close();
		} catch (FileNotFoundException e) {
			log.info(e.getMessage());
			e.printStackTrace();
			log.info("zip fail!");
			return false;
		} catch (IOException e) {
			log.info(e.getMessage());
			e.printStackTrace();
			log.info("zip fail!");
			return false;
		}
		log.info("zip success!");
		return true;
	}

	private static List<File> getAllFiles(File srcFile) {
		List<File> fileList = new LinkedList<File>();
		File[] tmp = srcFile.listFiles();

		for (int i = 0; i < tmp.length; i++) {
			if (tmp[i].isFile()) {
				fileList.add(tmp[i]);
				log.info("add file: " + tmp[i].getName());
			}
			if (tmp[i].isDirectory()) {
				if (tmp[i].listFiles().length != 0) {// 若不是空目录，则递归添加其下的目录和文件
					fileList.addAll(getAllFiles(tmp[i]));
				} else {// 若是空目录，则添加这个目录到fileList
					fileList.add(tmp[i]);
					log.info("add empty dir: " + tmp[i].getName());
				}
			}
		}
		return fileList;
	}

	/**
	 * 取相对路径 依据文件名和压缩源路径得到文件在压缩源路径下的相对路径
	 *
	 * @param dirPath
	 *            压缩源路径
	 * @param file
	 *
	 * @return 相对路径
	 */
	private static String getRelativePath(String dirPath, File file) {
		File dir = new File(dirPath);
		String relativePath = file.getName();
		while (true) {
			file = file.getParentFile();
			if (file == null) {
				break;
			}
			if (file.equals(dir)) {
				break;
			} else {
				relativePath = file.getName() + "/" + relativePath;
			}
		} // end while

		return relativePath;
	}

	/**
	 * 压缩成ZIP 方法1
	 * 
	 * @param srcDir
	 *            压缩文件夹路径
	 * @param out
	 *            压缩文件输出流
	 * @param KeepDirStructure
	 *            是否保留原来的目录结构,true:保留目录结构;
	 *            false:所有文件跑到压缩包根目录下(注意：不保留目录结构可能会出现同名文件,会压缩失败)
	 * @throws RuntimeException
	 *             压缩失败会抛出运行时异常
	 */
	public static void toZip(String srcDir, String target, boolean KeepDirStructure) throws RuntimeException {
		long start = System.currentTimeMillis();
		ZipOutputStream zos = null;
		try {
			OutputStream out = new FileOutputStream(new File(target));
			zos = new ZipOutputStream(out);
			File sourceFile = new File(srcDir);
			compress(sourceFile, zos, sourceFile.getName(), KeepDirStructure);
			long end = System.currentTimeMillis();
			log.info("压缩完成，耗时：" + (end - start) + " ms");
		} catch (Exception e) {
			throw new RuntimeException("zip error from ZipUtils", e);
		} finally {
			if (zos != null) {
				try {
					zos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

	public static void toZip(String srcDir, String target) throws RuntimeException {
		toZip(srcDir, target, true);
	}

	/**
	 * 
	 * 压缩成ZIP 方法2
	 * 
	 * @param srcFiles
	 *            需要压缩的文件列表
	 * 
	 * @param out
	 *            压缩文件输出流
	 * 
	 * @throws RuntimeException
	 *             压缩失败会抛出运行时异常
	 * 
	 */
	public static void toZip(List<File> srcFiles, OutputStream out) throws RuntimeException {
		long start = System.currentTimeMillis();
		ZipOutputStream zos = null;
		try {
			zos = new ZipOutputStream(out);
			for (File srcFile : srcFiles) {
				byte[] buf = new byte[BUFFER_SIZE];
				zos.putNextEntry(new ZipEntry(srcFile.getName()));
				int len;
				FileInputStream in = new FileInputStream(srcFile);
				while ((len = in.read(buf)) != -1) {
					zos.write(buf, 0, len);
				}
				zos.closeEntry();
				in.close();
			}
			long end = System.currentTimeMillis();
			log.info("压缩完成，耗时：" + (end - start) + " ms");
		} catch (Exception e) {
			throw new RuntimeException("zip error from ZipUtils", e);
		} finally {
			if (zos != null) {
				try {
					zos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}

			}

		}
	}

	/**
	 * 递归压缩方法
	 * 
	 * @param sourceFile
	 *            源文件
	 * @param zos
	 *            zip输出流
	 * @param name
	 *            压缩后的名称
	 * @param KeepDirStructure
	 *            是否保留原来的目录结构,true:保留目录结构;
	 *            false:所有文件跑到压缩包根目录下(注意：不保留目录结构可能会出现同名文件,会压缩失败)
	 * @throws Exception
	 */
	private static void compress(File sourceFile, ZipOutputStream zos, String name, boolean KeepDirStructure)
			throws Exception {
		byte[] buf = new byte[BUFFER_SIZE];
		if (sourceFile.isFile()) {
			// 向zip输出流中添加一个zip实体，构造器中name为zip实体的文件的名字
			zos.putNextEntry(new ZipEntry(name));
			// copy文件到zip输出流中
			int len;
			FileInputStream in = new FileInputStream(sourceFile);
			while ((len = in.read(buf)) != -1) {
				zos.write(buf, 0, len);
			}
			zos.closeEntry();
			in.close();
		} else {
			File[] listFiles = sourceFile.listFiles();
			if (listFiles == null || listFiles.length == 0) {
				// 需要保留原来的文件结构时,需要对空文件夹进行处理
				if (KeepDirStructure) {
					// 空文件夹的处理
					zos.putNextEntry(new ZipEntry(name + "/"));
					// 没有文件，不需要文件的copy
					zos.closeEntry();
				}
			} else {
				for (File file : listFiles) {
					// 判断是否需要保留原来的文件结构
					if (KeepDirStructure) {
						// 注意：file.getName()前面需要带上父文件夹的名字加一斜杠,
						// 不然最后压缩包中就不能保留原来的文件结构,即：所有文件都跑到压缩包根目录下了
						compress(file, zos, name + "/" + file.getName(), KeepDirStructure);
					} else {
						compress(file, zos, file.getName(), KeepDirStructure);
					}
				}
			}
		}
	}

}
